Patient benefit-risk preferences for targeted agents in the treatment of renal cell carcinoma.

BACKGROUND

Angiogenesis inhibitor agents have been shown to be effective in increasing progression-free survival (PFS) in patients with renal cell carcinoma (RCC); however, these treatments have different toxicity profiles.

OBJECTIVE

Our objective was to quantify patients' benefit-risk preferences for RCC treatments and relative importance of attributes in a common metric.

METHODS

US residents aged ≥18 years with RCC completed a web-enabled, choice-format conjoint survey that presented a series of 12 trade-off questions, each including a pair of hypothetical RCC treatment profiles. Each profile was defined by efficacy (PFS, when overall survival held constant), tolerability effects (fatigue/tiredness, diarrhoea, hand-foot syndrome [HFS], mouth sores) and serious adverse events (liver failure, blood clot). Trade-off questions were based on a predetermined experimental design with known statistical properties. Random-parameters logit was used to analyse the data.

RESULTS

A total of 138 patients completed the survey. PFS was the most important attribute for patients over the range of levels included in the survey, while remaining attributes were ranked in decreasing order of importance: fatigue/tiredness, diarrhoea, liver failure, HFS, blood clot and mouth sores. In order to increase PFS by 11 months, patients would be willing to accept a maximum level of absolute blood clot risk of 3.1% (95% CI 1.5, 5.3) or liver failure risk of 2.0% (95% CI 1.0, 3.3).

CONCLUSION

A 22-month change in PFS was shown to be the most important improvement for patients. Severe fatigue/tiredness and diarrhoea were rated as the most troublesome tolerability effects of RCC treatment. Patients were likely willing to accept significant treatment-related risks of 2-3% for liver failure and blood clot to increase PFS by 11 months.